Muffler



March 19, 1946. F. P. HUBER MUFFLER Filed Jul 11, 1944 2 Sheets-Sheet 1Fm; Pffu Zer F. P. HUBER Filed July 11, 1944 MUFFLER fSheets-Sheet 2grwamm' Patented Mar. 19, 1946 UNITED STATES PATENT OFFICE MUFFLER FrankP. Huber, New Orleans, La.

Application July 11, 1944, Serial No. 544,367

(or. 1s1-51) 1 Claim.

This invention relates to exhaust muiiiers for internal combustionengines.

An object of this invention is to provide a muiiier embodying theprovision of a suction means for drawing the gases out of the interiorthereof so as to eliminate back pressure in the engine.

Another object of this invention is to provide a muffler wherein thegases are mixed with air prior to the discharge of the gases into theatmosphere, the air mixing with the gases providing not only a suctionfor the removal of the gases, but also providing a cooling medium forcooling the gases prior to their discharge into the atmosphere, and theinitial expansion of the gases before discharge so as to therebyeliminate the explosive noise when the gases are discharged into theatmosphere.

A further object of this invention is to provide a muffler of this typewhich is designed particularly for airplane engines in which the forwardend of the muflier is formed as a scoop for drawing in air which willmaintain the mufller walls cool so that the metal will not disintegrateunder the heat of the gases.

With the foregoing objects and others which may hereinafter appear theinvention consists of the novel construction, combination andarrangement of parts as will be more specifically referred to andillustrated in the accompanying drawings wherein is shown an embodimentof the invention, but it is to be understood that changes, modificationsand variations may be resorted to which fall within the scope of theinvention as claimed.

In the drawings:

Figures 1 and 10 show a longitudinal section of a mufiler constructedaccording to an embodiment of this invention,

Figure 2 is a detail front elevation of the device,

Figure 3 is a detail rear elevation of the device, and

Figure 4 is a sectional view taken on the line 4-4 of Figure 1.

Referring to the drawings, the numeral I ll designates generally anouter jacket or shell which is substantially elliptical in transversesection and is provided with a flat bottom wall II. The bottom wall IIhas secured thereto a pair of longitudinally extending spaced apartL-shaped bracket members I2 and I3 which provide a means whereby themufller may be secured to a suitable support.

The front end of the jacket I is provided 'warclly reducing member ornozzle 2|.

with a flared scoop I4 for drawing air into the interior of the jacketand the rear portion of the jacket I0 is provided with a forwardlytapering member I5 having an oppositel flared tapered portion I6 securedto the reduced forward end thereof. The intermediate portion I6 hassecured thereto a cylindrical nipple or discharge member H. An innershell I8 which is substantially elliptical in transverse section isdisposed within the jacket It being substantially smaller in size thanthe jacket I0 so as to provide an air passage I9 between the outersurface of the inner member I8 and the jacket Ill. The inner member orshell I8 is secured to the upper side of the flat wall II and extendsthroughout the length of the wall H. The rear end of the inner shell ormember I8 is formed with a truncated conical intake member which hassecured to the rear small end thereof a for- The rear or large end ofthe nozzle 2| has secured thereto or formed integral therewith acylindrical nipple or intake member 22.

The forward end of the inner shell or member It has secured thereto aforwardly tapering discharge member 23 and a nipple 24 extends from thesmall end of the discharge member 23 and is positioned within thejunction of the outer members I5 and I6 terminating at its forward endwithin the rear portion of the intermediate tapered member I6, as shownin Figure 1a.

The discharge member 24 forms a reduced air space 25 which will producea venturi action so that when the air passes forwardly through the space25 the burned gases in the discharge member 24 will be drawn out of thismember and the air entering the forwardly enlarging member I6 will mixwith the burned gases so that the gases can initially expand and therebyeliminate the major portion of the explosive noise before these gasesare finally discharged from the discharge nipple I1. A plurality ofradially arranged bracmg or spacing bars 26 are interposed between theouter shell I0 and the inner shell I 8 at spaced points along the lengthof these members.

The inner member I 8 at its rear portion has mounted therein a conicalmember 21 provided with a plurality of openings 28 at a point rearwardlyfrom the apex thereof. The smaller apex portion of the conical member 21extends into the rearwardly reducing member 20, as shown in Figure 1,and the base or large end of the conical member 21 is secured as at 29to the inner shell I8. The inner shell or member I8 has positionedtherein a plurality of perforate baffle members 30 and ll. the latterbeing formed with a solid central portion 32. These baille members arespaced apart lengthwise oi the interior of the inner member is and therearmost battle it is rovided with central perforations 3t and a solidouter portion 35. The staggering o: the openings or perforations in theseveral baifles will term a tortuous passage for the gases passingthrough the inner member It. The inner member l8 at its forward portionhas secured therein a conical member 36 which is formed with openings 31and an open apex 38. The open apex 38 discharges centrally into therearportion of the discharge member 24, as shown in Figu e 1a.

In the use or this mufller the intake member 23 is adapted to beconnected to the exhaust; or an internal combustion engine, andpreferably,

this engine is an airplane engine with the bracket members l2 and I3secured lengthwise oi. the airplane and in a position where the scoop Itwill draw in air as the propellers connected to the engine are rotating.The exhaust gases will pass about the imperforate rear end portion ofthe conical member 2'7 and will initially enter the interior of theconical member through the perforations or openings rearwardiy of theapex thereof.

The burned gases will then pass through the openings in the bafiies 30,3t and 33 and will then enter the forward conical member 36. A portionof the gases will passcentrally through the conical member 36 andthrough the open apex thereof, whereas some oi. the burned gases willpass through the openings 3'5 in the conical member 36. The burned gaseswill enter the iorward discharge member 24 and will then mix in themixing chamber 39 formed in the intermediate mem her It. The air flowingthrough the space H between the jacket i and the inner member It willpass through the space 25 and will form a suction in addition toproviding an expansive medium where the burned gases can initially expand before being discharged through the for ward discharge nipple itinto the atmosphere.

The provision of the air space IS and the space 25 about the inner sheiiit provides a cooling medium for maintaining the inner member it cooland this moving air also provides a means for eliminating back pressureon the engine due to the venturi action at the discharge end or thedischarge member 24. The several parts forming the muiiier hereinbeioredescribed are secured together by spot welding or other suit-' ablefastening means. In the assembly or the device the inner tubular member[8 may initially have the battles 3| and 33 welded or flxed thereinafter which the conical members can be inserted and welded and thetapered end portions 20 and 23 may then be electrically welded or thelike to the ends of the tubular member It. The bracing members 26 arewelded or fixed to the tubular member is before insertion of this memberin the jacket and after insertion in the jacket ID, the latter may bespot welded or the like to the bracing members and associated parts.

What I claim is:

A muflier comprising an inner tubular member, tapered members extendingfrom the opposite ends of said inner member, an intake nipple connectedto the reduced end of one of said tapered members, a pair of oppositelyextending apertured conical members disposed within said inner tubularmember and having the bases thereof secured to the latter with theapieces thereof outermost and with the bases thereof spaced apart, theapex of one of said conical members being formed with an opening, saidconical members having the small ends thereof projecting into saidtapered members, an outer jacket disposed in spaced relation about saidinner tubular member, a flared scoop at one end of said jacket, atapered jacket at the other end of said outer jacket and engagingloosely about an adjacent one of said first tapered members, a forwardlyflared member extending from the small end of said tapered jacket, aforwardly extending discharge nipple extending from the forward smaliend of the other of said tapered members and disposed'partly within saidtapered jacket and partly within said forwardly flared member and aplurality of apertured bafiles fixed in said inner tubular memberbetween the bases of said conical members and having the aperturesanranged to form a tortuous passage.

FRANK P. man.

